Storage area networks (SANs) are increasingly used by enterprises and other hosts to store large amounts of data. Many SANs include host and storage devices having different supported protocols to take advantage of different associated capabilities (e.g. bandwidth or physical range). Exemplary protocols supported by devices in a SAN can include InfiniBand (IB), Serial Attached Small Computer System Interface (SAS), Internet Small Computer System Interface (iSCSI), Serial Advanced Technology Attachment (SATA) or Fibre Channel (FC) for example, although other protocols are also used. Some of these protocols allow/facilitate in-order frame sequencing and other of these protocols allow/facilitate out-of-order frame sequencing.
In order to facilitate communications between the host and storage devices, SANs can include multi-protocol switch processing devices that convert incoming and outgoing frames depending on the protocols respectively supported by the host and storage devices for each transaction. Accordingly, the multi-protocol switch processing device may be handling traffic associated with various protocols requiring in-order and out-of-order frame sequencing. Due to the use of protocols requiring both in-order and out-of-order frame sequencing, multi-protocol SANs often experience significant frame drops/loss and associated retransmissions, out of order delivery, and frame misdirection, among other undesirable effects on the performance of the SAN.
Currently, frame order control methods include lock and release mechanisms implemented by a multi-protocol switch processing device that prevent out-of-order frames from being received and processed. Accordingly, these frame order control methods are only effective for SANs in which the host and storage devices both support protocols requiring in-order frame sequencing (e.g., FC and SATA), and are ineffective for controlling frame order for host and storage devices supporting protocols requiring out-of-order frame sequencing. Therefore, current frame order control methods do not effectively mitigate the undesirable performance issues present in SANs having devices supporting protocols requiring out-of-order and in-order frame sequencing.